NUsolar

Do you have a vision for what our upcoming solar car should look like?

Use the template of our car here: http://i.imgur.com/tUlpE.jpg, and draw it out! Or, just describe it in text. Either way, send it to team@nusolar.org and we’ll take a look.

Thanks, we look forward to seeing your ideas!

(Do not draw on this preview, use the full-size version at http://i.imgur.com/tUlpE.jpg)

The team would like to thank Porteous Fastener Company for their contribution of bolts! These will come in handy as we continue assembling our new car. Porteous Fastener Company is a leading distributor of fasteners based in the west coast, which strives to offer excellent customer service.

We have completed both the top shell and bottom shell of our upcoming car! The process of doing carbon fiber layups on our molds and taking our molds to Precision Quincy to be cured in their industrial oven took 6 days. We did the very first layups on the top shell Thursday night, and the bottom shell was cured at Precision Quincy yesterday, but we brought it back this morning. Throughout the last 6 days, the team spent over 65 hours completing the carbon fiber layups, transporting them between Northwestern and Precision Quincy, and monitoring the oven cures. All while still attending our regular classes, or at least trying our best to.

Here are some team members working on the carbon fiber layups. We did most of the layup work at night, then brought them to Precision Quincy as early as possible in the morning for a full day of oven time. We did the top shell layup in one marathon all-night session, but the bottom shell had a more complicated shape, and we spent multiple days on it.

Applying surfacing film to the top shell mold. Surfacing film gives a smooth exterior surface.

Adding a carbon fiber layer over film adhesive on the bottom shell. Film adhesive goes between Nomex and carbon fiber sheets, and helps the two bond to each other.

This is the enormous oven we cured our layups in, towering over Jonathan to the left.  We haven’t done any calculations, but you could probably bake a cookie for every student at Northwestern (16,475 students) in one go using it.

Here are the top and bottom shells freed from their molds. The excess carbon fiber on the edges still needs to be trimmed off, but the parts do not appear to have any major problems.

Top shell

Bottom Shell

It is very exciting to be done with this crucial step of creating our upcoming car, especially because we can see it’s final shape now. However, we still have a lot of work to do, such as creating reinforcing ribs to give the car strength, so stay tuned for more updates!

See more from our layup process at our Facebook page, www.facebook.com/WeRaceSolarCars, and be sure to Like us on Facebook as well!

Tonight, we did a simulated carbon fiber layup on our mold (with everything but the carbon fiber) to see if everything was working as it should, and so everyone on the team understands how the process works.

We began by resting 2-3 layers of breather fabric over the mold. Breather fabric is a sheet of cottony material that allows air to flow  throughout the mold, maintaining constant vacuum pressure throughout. Next, we made a border around the mold with butyl strips in order to form an airtight seal, and placed the vacuum bag over the mold. This step was tedious since we had to make many pleats along the edge to keep the bag from bunching together, while remaining able to conform to the shape of our mold. After that, we turned on the vacuum pump and checked for any leaks. It was an exciting moment watching the air first begin to evacuate the vacuum bag, but soon we had to start thinking of ways to fix minor leaks and pressure issues – not surprising given how large the mold is.

We’ll be doing the real carbon fiber layups very soon, so hopefully they turn out well. I think everyone on the team learned something useful from tonight’s work session, so as long as all of us bring that to the real layups, we should be in good shape.

NUsolar would like to thank The Young Engineers for providing us with grommets! These pieces will protect the bolt holes in the Nomex and carbon fiber panels in our car, by spreading force and preventing the bolts from crushing the Nomex material.

The Young Engineers develops advanced fasteners and other products for the aerospace industry, and is based in Lake Forest, CA.

We’d like to thank Aurora Bearing Company for their generous support in helping us obtain bearings and rod ends to be used in our new suspension system.

Founded in 1971, Aurora Bearings has grown to become a world leader in the rod end and spherical bearing industry. They carry a complete line of standard rod ends and spherical bearings, and  can also create custom units, primarily serving the aerospace and military industries.

NUsolar would like to thank Fastener Mart for their generous donation of flex-loc nuts, which will ensure that the components of our car can stay tight together, even under rough road vibrations and shock.

Fastener Mart carries over 28,000 different bolts, screws, washers, nuts, metric fasteners, anchors, pins, rings, rivets, rods and more. They sell to both individuals and businesses with no minimum order, and ship same day if possible. We absolutely thought they were a pleasure to work with!

Nothing like waking up early to the smell of some fresh baked goods, huh? Well instead, we woke up super early yesterday to drive our mold out to Woodstock, IL, home of Precision Quincy, who manufactures ovens and communications shelters.   They’ve got an oven big enough for our mold to fit in, so we threw it in for a post-cure so it can sustain 350ºF temperatures for the carbon fiber cure.  We also threw in the bubble mold to prepare it for thermoforming, which will be happening at Profile Plastics in the next few weeks!

Thanks to Precision Quincy for letting us use their oven!  We’ll be back on Friday and Saturday to do our carbon fiber layups for the shell!

We got all the foam off the mold earlier this week and applied another surface coat to it. This was the first time we saw the mold, and although there are a couple small areas that will definitely need some fixing, overall it turned out pretty well.

Team members removing the last of the foam from the mold

Tonight we went to the Autobay to sand the mold after our 9:00 team meeting, and made a lot of progress. Tomorrow we will continue to sand in preparation for this weekend, when we will be taking the mold to a local industrial oven for a post-cure heat treatment. Road trip!

Sanding the mold with orbital sanders and sandpaper

Also, our solar array shipped from Arizona and we are intently tracking it on FedEx’s website, it should be here very soon!

We’ve re-uploaded the timelapse video of our bottom shell fiberglass mold process with added sound and labels. I hope that makes it a little easier to digest!

It’s difficult to find great music to put in YouTube videos without infringing copyrights, so thanks SGX for letting us use your awesome music!